<<

4.6 ­ and Fit Lines

Wednesday, November 9, 2016

Students write equations of best­fit lines using linear regression, and write equations of median fit lines.

1 4.6 ­ Linear Regression and Median Fit Lines

Homework.

2 4.6 ­ Linear Regression and Median Fit Lines

3 4.6 ­ Linear Regression and Median Fit Lines

4.1 Vocab.

Slope ­ Intercept Form ­ An equation in the form y = mx + b

Constant Functions ­ Written in intercept form as y = 0x + b, or y = b

4.3 Vocab.

Point ­ Slope Form ­ An equation in the

form y ­ y1 = m(x­x1)

4 4.6 ­ Linear Regression and Median Fit Lines

Best­Fit Line ­ A very precise line of fit.

Linear Regression ­ A complex algorithm that calculates the best­fit line.

Correlation Coefficient ­ This number, r, tells you if the correlation is positive or negative and how closely the best fit line models the . The number, r, is always between ­1 and 1.

5 4.6 ­ Linear Regression and Median Fit Lines

6 4.6 ­ Linear Regression and Median Fit Lines

Correlation Coefficient, r

If r is greater than zero and less than or equal to 1. We have a positive correlation. The closer it is to 1, the stronger the positive association is.

If r is greater than or equal to ­1 and less than 0. We have a negative correlation. The closer we get to ­1, the stronger the negative correlation is.

7 4.6 ­ Linear Regression and Median Fit Lines

Regression Line: y = .23206x + ­456.032 Correlation Coefficient: .875515

8 4.6 ­ Linear Regression and Median Fit Lines

9 4.6 ­ Linear Regression and Median Fit Lines

Regression Line:

Correlation Coefficient:

10 4.6 ­ Linear Regression and Median Fit Lines

Regression Line:

Correlation Coefficient:

11 4.6 ­ Linear Regression and Median Fit Lines

Regression Line

Median Fit Line

Correlation Coefficient

12 4.6 ­ Linear Regression and Median Fit Lines

Regression Line

Median Fit Line

Correlation Coefficient

13